07+ Civic Si Sedan Toda K20Z High Power Exhaust ManifoldPrimary Runners: 45mm
4-1 exhaust manifolds (headers) are normally designed for high end horse power, but the problems is sacrificing low-end torque and mid-range power which leads to sluggish performance. TODA Racing designed 4-2-1 Tri-Y piping design with various piping diameter, tapper design collector creates scavenging affect so exhaust velocity is increased.
Middle Section: 55mm
Compatible with US 4 door Civic SI (FA5 Chassis) under the condition both exhaust manifold and TODA exhaust systems (18000-FD2-00J) are used together.
OEM O2 Sensor harness extension required.
Addtional O2 sensor for A/F ratio meter included.
*For Competition Use Only. Factory Catalyst cannot be used.